Heating device

ABSTRACT

In a heating device, a material is heated by heat from a hydration reaction with an exothermic material and water. A container for the material heated is provided above a container for the exothermic material and has a number of apertures at a bottom wall of the portion for containing the material to be heated. The apertures spout vapor of a high temperature generated by the heat of hydration reaction with the exothermic material and water to the inside of the container for the material to be heated so that the vapor of high temperature is added to the material to be heated from right below the material to be heated in addition to conductive heat transferred through a wall of the portion for containing the material to be heated.

FIELD OF THE INVENTION

The present invention relates to a heating device which make a materialto be heated by heat of hydration reaction of an exothermic material andwater.

BACKGROUND OF THE INVENTION

As a heating device for easily heating drinks such as coffee, tea and soforth or cooked foods, there have been provided heating devices whichuse by heat of hydration reaction between an exothermic material andwater.

However, in these conventional heating devices, as seen in, for example,Japanese patent publication (kokai) No. 62-16371 and 61-259974, andJapanese utility model publication (kaukoku) No. 62-32500, Europeanpatent publication No. 3231513, Japanese utility model publication(koukai) No. 61-35, a portion for containing a material to be heated anda exothermic part are parted by a partion wall or walls of container andthe material to be heated is heated only by conductive heat transferredtherethrough. As a result, therefore, a part of the material to beheated contacting with the wall is heated to a high temperature, whileother parts distant from tile wall can not be heated until they reach asufficient temperature. Especially, in the case when a material to beheated is a solid, this tendency becomes remarkable; that is, the partin contact with the wall is scorched but an inner temperature is notraised sufficiently.

The heating devices, described in Japanese utility model publication(koukai) Nos. 62-123742 and 61-137318, have an aperture at a bottomwall. The vapor produced by heat of hydration reaction can heat thematerials to be heated without causing uneveness of temperature, asdescribed above.

In the heating devices described in Japanese utility publication(koukai) Nos. 62-123742 and 61-137318, it is a problem that small piecesof the exothermic material may be attached to the material to be heatedtogether with the vapor of high temperature through apertures of theportion for containing the material to be heated.

The object of the present invention is to provide heating device inwhich small pieces of the exothermic materials spattered by reaction ofthe exothermic material and water does not tend to attach to thematerial to be heated.

Then, the heating device described above is one in which the exothermicmaterial and water after hydration reaction are mounted with unremovedoff, as disclosed in Japanese patent publication (koukai) No. 62-16371,and one in which exothermic materials or a bag containing the exothermicmaterials is directly included, as Japanese utility model (koukai) No.61-137318, the device, after having made hydration reaction of theexothermic materials could not be re-used.

The other object of the present invention is to provide a cartridge-typeheating device comprising portion a for containing the exothermicmaterials, which is applied to different styles of the heat devices, andalso the heating devices are reusable.

DISCLOSURE OF THE INVENTION

The present invention is based on a heating device which consists of abag containing water, a bag containing the exothermic materials whichgenerate heats by contacting with water and an insulation container inwhich a sheet-type filter element which allows the vapor of hightemperature to pass but prevents the exothermic material from passing isspread on an opening and a means for starting contact with theexothermic material and water operable from the outside of theinsulation container.

Therefore, this filter element of the portion for containing the heatingmaterials enables the vapor of high temperature caused by heating to goout of the portion, but it prevents pieces of the exothermic materialsreacting with water from passing through the portion and thus theexothermic materials are not attached to the materials to be heated.

As described above, such a cartridge-type device is applied to differentstyles of the heat devices. If the portion containing the exothermicmaterials is exchanged after use, the heating device body can be reusedmany times.

It is preferable that a means for starting contact between water andexothermic materials is a tape-type one by which a bag containing watercan be torn so that water may evenly contact with the whole exothermicmaterials.

It is desirable to place the portion for containing the material to beheated and the portion for containing the material in a containercovered with a lid which can be opened and closed, since the material tobe heated is also heated from the upper side due to the vapor of hightemperature filled in the portion for containing the material to beheated.

On the other hand, it is desirable to provide a cut or slit to dischargeoutside vapor having entered in the portion for containing the materialto be heated, since the vapor having decreased in temperature after theheating, which could remain in the portion for containing the materialto be heated, will not heat any materials to be heated sufficiently, andproduce a large quantity of dew inside of the lid, or blow off tile lidby the internal pressure. By providing such a cut, the vapor havingdecreased in temperature after heating the material to be heated ispushed out by new vapor produced afterwards through the cut, thus alwayskeeping the portion for containing the material to be heated filled withthe vapor of high temperature until the vapor production is stopped.

As an exothermic material, calcium oxide, magnesium chloride, calciumchloride, iron oxide and so on can be used, for example. This materialwill generate heat of hydration reaction by contacting with water.Calcium oxide is most preferred as it generates high heat of hydrationreaction, and boils water in contact with it, thus producing a largequantity of vapor of a high temperature.

It is preferable that this portion containing the exothermic materialsis placed at the lower of the portion for containing the material to beheated which bottom wall has apertures to-pass the vapor, so that thematerial to be heated is heated by the high temperature vapor spoutingout from directly under the material to be heated, in addition toconductive heat transferred through a bottom wall, thus heated withoutcausing unevenness of temperature and also, small pieces of theexothermic materials are not spattered, so that the material to beheated is polluted with the exothermic materials.

Anything can be used as a material to be heated as long as heating isnecessary, although taste of cooked food is increased by re-heating. Itis effective to place an uncovered material to be heated in the portionfor containing the material to be heated, but in the case when amaterial to be heated is liquid such as soup, it is placed in a style ofretort pack when contained in the portion for containing the material tobe heated.

Further scope of applicability of the present invention will becomeapparent from the detailed description given hereinafter. However, itshould be understood that the detailed description and specificexamples, while indicating preferred embodiments of the invention, aregiven by way of illustration only, since various changes andmodifications within the spirit and scope of the invention will becomeapparent to those skilled in the art from this detailed description.

BRIEF DESCRIPTION OF THE DRAWINGS

The present invention will become more fully understood from thedetailed description given hereinbelow and the accompanying drawingswhich are given by way of illustration only, and thus are not limitativeof the present invention, and wherein:

FIGS. 1 to 5 are explanatory views of a heating apparatus according tothe preferred embodiment I of the present invention, in which;

FIG. 1 is a perspective view of the heating device;

FIG. 2 is a longitudinal-sectional view of the heating device;

FIG. 2A is an enlarged view of the slit apertures in the wavy bottomwall;

FIG. 3 is a perspective view of the heating device;

FIG. 4 is a longitudinal-sectional view of a portion for containing anexothermic material;

FIG. 5 shows a container;

FIGS. 6, 7, 8, 9 and 10 are explanatory views of a heating deviceaccording to the preferred embodiment II of the present invention, inwhich;

FIG. 6 is a perspective view of the heating device;

FIG. 7 is a sectional view of a cut; and

FIGS. 8, 9 and 10 are plan views showing other shapes of a cut.

FIG. 11 is a sectional view of embodiment III of the present invention;

FIG. 12 is a perspective view of embodiment III of the presentinvention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

The tear element 7 is not limited to a tape-shape as described above,but it may be a sharp-pointed stick type. In this case, the water bag isbroken by piercing it with the tear element from the opening.

The tear tape 7 may be deposited to both of the bag for the exothermicmaterial 5a and the bag for water 5b so that both bags 5a and 5b can bebroken at the same time.

The insulation container 6 prevents the exothermic source 5 and thecontainer 2 from directly contacting with each other in order to preventthe container from melting or deformation by the heat generated from theexothermic source 5. The insulation container 6 is a flat box which hasan opening at the top, inside of which the exothermic source 5 iscontained. A sheet-type filter material 8 which allows the vapor of hightemperature to pass but prevents small pieces of the exothermic materialfrom passing through is spread on the upper opening. A nonwoven fabricmay be used as the filter material 8.

The portion for containing the exothermic material 4 is acartridge-type, and is contained in the container in a removable way,that is, the container can be reused by replacing a used container ofthe exothermic material 4 with an unused one. Moreover, the portion forcontaining the exothermic material 4 and the container 2 may beconstituted in a body to be used in a disposable way.

The container 2 is, as shown in FIG. 3, a flat cubic box having areleased top and is made of styrene foam. At the bottom of the container2, a partition 9 extruding inward from a bottom wall 2a is formed, thuspartitioning and forming a portion 10 for containing the portion forcontaining the exothermic material 4.

The container 3 is made of plastic, formed in a body. The container 3includes an engagement part 3a formed at the edge of the outsideperiphery of the container 3 to engage the container 3 to the outsideperiphery at the top of the opening of the container 2, and ispartitioned by isolating walls 14 to form a first portion for containinga material to be heated 11, a second portion for containing a materialto be heated 12, both located above the portion for containing theexothermic material 4, and a portion for containing an material not tobe heated 13 located away from the portion for containing the exothermicmaterial 4. Further, engagement ribs 3b are fixed in at a predeterminedinterval around the whole periphery of the engagement part 3a.

The portion for containing the material to be heated consists of thefirst container 11 to contain cooked rice A and the second container 12to contain articles of other foods which require heating; in otherwords, which increase the taste thereof when heated. On the other hand,the portion for containing the material not to be heated is to containfruit or articles of food which do not need the heating; that is, whichtaste better when they are cold. This is further partitioned three smallcontainers 13a, 13b and 13c.

Concavities 18 and 18 to which respective partition ribs 17a and 17b ofa lid 1 as described later are engaged are formed at the isolating wall14 between the first container 11 and the second container 12 and theisolating wall 14 between the second container 12 and the portion forcontaining the material not to be heated 13, out of all the isolatingwalls 14.

As shown in FIG. 2, sections of respective bottom walls 11a and 12a ofthe portions for containing the materials to be heated 11 and 12 areformed in a wavy way, thus having larger surface area so as to make theheat conduction more effectively. Furthermore, as shown in FIG. 5, anumber of slit-shaped apertures 15 are formed at a certain interval onthe wavy bottom walls 11a and 12a to spout out the vapor of hightemperature from downward into the portions for containing the materialsto be heated 11 and 12. Moreover, at the top of the isolating wall 14located between the first containing portion 11 and the secondcontaining portion 12, a slit-shaped aperture 16 is formed to spout outthe vapor of high temperature from upward into the first containingportion 11.

As shown in FIG. 2, when the container 3 is attached to the container 2,as the portion for containing the material not to be heated 13 iscompletely isolated from the portion 10 containing the insulationcontainer 6 by the partition 9 of the container 2, it is ensusceptibleto the exothermic reaction from the portion for containing theexothermic material 4.

The lid 1 to cover the container 2 is, similar to the container 3, madeof plastic, formed in a body, having an engagement part 1a to engage theengagement part 3a of the container 3 at the edge of the outsideperiphery in a state in which the engagement part 1a covers with theengagement part 3a and inner surfaces 1b to be faced to the top of eachisolating wall 14 of the container 3. At the inner surfacescorresponding to the isolating wall 14 between the first and secondportions for containing the materials to be heated 11 and 12, and to thewall 14 between the second portion for containing the material to beheated and the portion for containing the material not to be heated 13,the above mentioned partition ribs 17a and 17b are provided. As shown inFIG. 2, the partition rib 17a facing to the concavity 18 of theisolating wall 14 between the first container portion 11 and the secondcontainer portion 12 is provided in such a manner as a facing part ofthe partition rib 17a is located at the outside (on the right side inFIG. 2) of an aperture 16 for spouting out the vapor of hightemperature.

The present invention is explained in more detail in the attacheddrawings.

FIG. 1 through FIG. 5 show a heating device according to a firstembodiment of the invention.

The heating device shown in the figures is a lunch box for Japanesefood, in which a container for contents of food 3 for containing food asa material to be heated is provided inside of a container 2 which can beopened and closed by a lid 1, while a portion for containing anexothermic material 4 to heat the food is provided below the container3, presenting a shape of a flat box.

As shown in FIG. 4, the portion for containing an exothermic materialcomprises an exothermic source 5 and an insulation container 6 forcontaining the source 5.

The exothermic source 5 consists of materials which generate heat byhydration reaction, concretely, of calcium oxide (CaO) and water.Although calcium oxide can be used as it is, it is better to pack it ina bag for easier handling, namely, the exothermic source 5 includes abag for containing the exothermic material 5a containing calcium oxideand a bag for containing water 5b provided below the bag 5a. The bag forthe exothermic material 5a is made of aluminium foil and a number ofsmall holes is formed on the whole surface thereof, while the bag isfilled with calcium oxide as an exothermic material. The bag for water5b is made of a plastic film such as polyethylene and so on, which isfilled with water, while a tear element 7 for the water bag 5b isprovided on the upper surface thereof. The exothermic material bag maybe made of a nonwoven fabric, as well as aluminum foil.

The tear element 7 has a tape-shape, having large tensile strength, andis deposited to the water bag 5b so that by pulling the tear element 7,the plastic film constituting the water bag 5b is torn in the directionof the extending of the plastic film, the width of which is relative tothe width of the tear element. When the water bag 5b is broken, waterenters inside of the bag 5a through the small holes of the bag for theexothermic material 5a, thus starting contact with the exothermicmaterial.

An opening is provided at a side wall of the insulation container 6 andfurther, an opening 20 is provided at a side wall 2b of the container 2.The tear element 7 passes through these openings and the tip thereof canbe seen from an outer wall of the container 2, so that the tear element7 can be pulled from the outside of the container 2. Moreover, a markshowing a limit of the length to be pulled is provided midway on thetear element 7.

As described above, in this embodiment shown in the figures, thetape-shaped tear element 7, a means for starting contact with theexothermic material and water is extruded from the container 2 throughthe opening 20 at the side wall 2b of the container 2. Alternatively, itmay extend from an aperture between the container 2 and the container 3without providing the opening 20. Further, instead of providing theopening at the side wall of the insulation container 6, a cut may beprovided at the upper edge of the side wall of the insulation container6 so that the tear element 7 can pass through the cut.

Therefore, in the state in which the container 2 is covered with the lid1, as the surfaces 1b are in contact with the top of each isolating wall14b the portions for containing the materials to be heated 11 and 12 andthe portion for containing the material not to be heated 13 forms sealedapertures completely isolated with each other. Especially, at theisolating wall 14 between the first container 11 and the secondcontainer 12, and at the isolating wall 14 between the second container12 and the portion for containing the material not to be heated 13, highsealing performance is ensured due to the respective attachment of tilepartition ribs 17a and 17b of the lid I to the concavities 18 and 18 ofthe container 3.

Now, upon using the heating device constituted as described above,cooked rice A, and other articles of food B and C are placed in eachcontainer 11, 12 and 13, respectively, after the container 3 is placedin the container 2, then, the lid 1 is placed on the upper surface ofthe container 2. Upon eating the contained foods A, B and C, forexample, a few hours later, the portion for containing the exothermicmaterial 4 provided inside of the heating device is operated and amongthe foods described above, only tile foods A and B contained in theportions for containing the materials to be heated 11 and 12,respectively, are heated.

The heating process of the above-mentioned heating device is explained.

The tear element 7 extending outside of the container 2 is pulled untilthe mark 9 showing the limit of the length to be pulled is seen from theoutside.

Then the water bag 5b in the portion for containing the exothermicmaterial is torn and water contained therein touches calcium oxidecontained in the exothermic material bag 5a, which causes calcium oxideto vigorously generate heat together with the vapor of high temperaturedue to the hydration reaction.

Moreover, at this time, as the water bag 5b is provided below theexothermic material bag 5a and a number of small holes are provided onthe exothermic material bag 5a, water in the water bag 5b permeatesupward through the small holes of the exothermic material bag 5a due tocapillary phenomena, resulting in uniform and gradual contact with waterand the whole calcium oxide inside of the exothermic material bag 5a.Accordingly, the process of heat generation of calcium oxide is highlyeffective and its duration time is long.

The vapor of high temperature is sent to the portions for containing thematerials to be heated 11 and 12 in the container 3 through the filtermaterial 8 of the insulation container 6, and then through the apertures15, 16 in the container 3, thus heating the foods A and B in thecontainers 11 and 12 together with the conductive heat transferredthrough walls of the container 3.

Thus, as the vapor of high temperature spouts not only from downward butalso from upward, the rice A contained in the first container 11 isheated both from the top and bottom.

Still, the food C in the container for the material not to be heated 13is not heated, as the container for the material not to be heated 13 inthe container 3 is provided away from the heating device and further thepartition rib 17b attaching to the concave 18 of the partition wall 14of the container 3 is provided.

The vapor of high temperature is filtered by the filter material 8 sothat it enters the containers for the materials to be heated 11 and 12only after impurities such as calcium oxide and calcium hydroxidegenerated by the reaction of calcium oxide and water have been removed,whereby decrease in tastes of the rice A and the articles of food B bythe impurities is prevented.

Further, the vapor in the first container 11 and that in the secondcontainer 12 are not mixed, which prevents the vapor reeking of thearticles of food B from contacting with the rice A and vice versa, thuspreserving the tastes from decreasing with the mixture of the smells.

As only the rice A and the articles of food B which increase theirtastes when they are hot are heated, and the articles of food C whichincrease their tastes when they are cold remain cold, a more tasty mealcan be obtained.

The present invention can also be utilized as a heating device forheating retort-packed food contained in a bag made of aluminium orinstant food cooked only by heating and so on, other than as a lunch boxas described in the preferred embodiment I.

Moreover, the heating device may be constituted in such a way in whichwhile providing the apertures 15, 16 spouting the vapor in the firstcontainer 11, such apertures are not provided in the second container12, so that the articles of food 9 are heated without using the vapor.In this case, if the container 3 is made of aluminum, it is possible toappropriately bake the articles of food B in the second container 12.

FIGS. 6 to 10 show a heating device according to the preferredembodiment II of the present invention.

In the above-mentioned heating device according to the preferredembodiment I, the lid 1 is a sealing lid and therefore, if the vapor thevolume of which is more than that of the portions for containing thematerials to be heated 11 and 12 enters the containers 11 and 12,heating of the materials to be heated may be done insufficiently, or thetastes of food may be decreased because of dew of the vapor attaching toor permeating into the material to be heated. Further, in the case inwhich the sealing between the container and the lid is not appropriate,the vapor of high temperature may spout from a aperture between thecontainer and the lid, or the lid may be blown off.

Accordingly, as shown in FIG. 6, a small cut 19 is provided on a lid 1of the heating device according to the preferred embodiment II, so thatthe vapor in excess of the volume of the portion for containing thematerial to be heated in the container is gradually discharged throughthe cut 19 to the outside, thus inside of the container is always keptfilled with the vapor of high temperature newly generated.

Moreover, a state of heating inside of the portion for containing thematerial to be heated can be detected from the vapor being dischargedfrom the cut 19.

In the case in which the portion for containing the material to beheated is divided into some parts, such cut 19 is not required to beprovided at the lid corresponding to the container on which the vaporremained therein or the dew generated do not have any adverse effect.

Such cut 19 may be provided at the lid corresponding to the containerfor the material not to be heated. By providing the cut 19 at such alocation, even if the vapor enters the container f or the material notto be heated as a result of deformation or a damage of the isolatingwall between the portion for containing the material to be heated andthe portion for containing the material not to be heated, the vapor canbe discharged.

Plurality of the cuts 19 may be provided at every location correspondingto the partitioned portions for containing the material to be heated, sothat the vapor having entered the portions for containing the materialto be heated can be discharged in a short time.

FIG. 7 shows a longitudinal sectional view of the cut 19. As shown withtwo-dot chain lines, the cut may be lifted upward. In this case, as anopening for discharge of the vapor is made bigger, the vapor in theportion for containing the material to be heated is discharged in ashorter time.

In the case as shown in FIG. 6, the cut has a V-shape, but a variety ofshapes can be considered as shown in FIGS. 8 to 10.

A cut shown in FIG. 8, for example, has an U-shape, a cut shown in FIG.9 has approximately a trapezoid-shape, and a cut shown in FIG. 10approximately has a rectangular shape.

As described above, according to the present invention, in a heatingdevice with use of heat of hydration reaction between an exothermicmaterial and water spattering of the exothermic material on thehydration reaction can be avoided.

Further, the heating device according to the present invention can beproduced as a cartridge-type one which contains an exothermic materialbag and a water bag, so that such a device can be utilized as a heatingsource which is applicable to any heating apparatus.

The heating device according to the present invention is, therefore,made simple but increases its uses compared to a conventional heatingdevice utilizing heat of hydration reaction with limited uses.

Thus, the heating device according to the preferred embodiment III canalso be applied to the material to be heated, such as the "instant bakednoodle", which requires to add a small quantity of water upon heating.

A heating device 21 comprises a container 22, a container for contentsof food 23 placed in the container 22 and an insulation container 24,with a material to be heated D contained in the container 23 and anexothermic material contained in the insulation container 24.

The container 22 made of styrene foam is an approximately square boxwith its upper surface released, to which the container 23 is attachedat an opening 22a of the upper side and the insulation container 24 isplaced on a flat bottom wall 22b. An edge portion 22c is formed aroundthe periphery of tho opening 22a, to which an engagement part 23c of thecontainer 23 is engaged. The inner diameter of the container 22 isslightly larger than the outer diameter of tile container 23 so thatapertures G1 are produced between side walls 22d and 23g of thecontainer 22 and the container 23. Further, although an illustration isomitted, an end of the edge portion 22c is formed slightly irregularlyso that a small aperture G2 is formed between the end of the edgeportion and the end of the edge of the engagement part 23c, which makesit possible to lead the atmosphere to the side of the insulationcontainer 24 through this small aperture and then, through the apertureG1.

The container is also approximately square, with an opening 23a at theupper surface thereof, and is made of plastic in a body. While amaterial to be heated such as the "instant baked noodle" is placed on abottom wall 23b, a lid 26 as will be explained later is set at theengagement part 23c provided around the outside periphery of thecontainer 23 to cover the opening 22a. Further, a fixing rib 23d isfixed in the engagement part 23c around the whole periphery at a certaininterval. The bottom wall 23b has a wavy surface to have a largersurface area so that heat conduction is performed effectively. A numberof apertures 23e and 23f in a slit-shape are formed at the concavitiesand the convexities of the bottom wall 23b, respectively, so that whilewater poured in the container 23 Is dropped in the direction of theinsulation container 24 through the aperture 23c at the bottom, thevapor of high temperature generated by the hydration reaction isspouting in the direction of the container 23 through the apertures 23eand 23f.

The insulation container 24 has a dish-shape, which contains anexothermic material 25, which will be described later, and prevents theexothermic material 25 and the container 22 from directly contactingwith each other, so as to avoid the melting or transformation of themain body of the container by the heat generated from the exothermicmaterial 25. As the exothermic material 25, such materials whichgenerate heat by hydration reaction is calcium oxide and so on are used.In the preferred embodiment III, a certain amount of calcium oxidenecessary to cook tile material to be hosted D is filled in a nonwovenfabric having good water absorption, and then placed and contained inthe insulation container 24. Further, the amount of calcium oxide to befilled is set tn advance according to the content of food, and thetemperature of heat is adjustable in the range of about 103° C. to 330°C.

A lid 26 having an equal diameter with an outside diameter of thecontainer 23 is made of plastic, and at the edge of the outsideperiphery thereof, an engagement part 26a is formed so that by engagingit to the engagement part 23c of the container 23, the respectiveopening, 22, and 23a of the containers 22 and 23 are covered, whichmakes the container 23 a sealed aperture E.

A quantity of water to be added to the exothermic material 25 may bepredetermined as much as required to cook the food to be contained inthe container 23 and it may be indicated at a side of the lid 26 or ofthe container 22 or, as shown in FIG. 12, a cup of a fixed quantity suchas a folding paper cup may be provided and placed in the folded state onthe upper surface of the lid 26 and so on. Owing to this, properhydration reaction with the exothermic material 25 takes place, thusavoiding uneven heating of food due to excess and deficiency of thequantity of water, and decrease in tastes due to insufficient heating.

Cooking upon using the heating device constituted as described above forcooking the dried noodles of the "instant baked noodles" is explainednext.

The lid 26 having placed on the container 23 is removed and, as shown inFIG. 12, water is poured from the upside of the container 23 to theapproximately whole surface of the dried noodles in a scattering way andthen the opening 23a of the container 23 is immediately covered with thelid 26 again. Water having poured into the dried noodles adds propermoisture to the dried noodles, thus some water loosening the driednoodles. However, most water is gathered at the concavities of thebottom wall 23b of the container 23 to drop through the aperture 23e ateach concavity. Then when the dropped water is poured into theapproximately whole surface of exothermic material (calcium oxide), theexothermic material 25 generates heat vigorously due to the hydrationreaction of the exothermic material, generating the vapor of hightemperature. At this time, an air supply to the exothermic material ismade through the aperture G1 and the small aperture G2.

The vapor of high temperature is generated for a minute or two, raisingup through the respective apertures 23e and 23f of the convexities andthe concavities at the bottom wall 23b, and is filled in the container23.

Due to this, the noodles are sufficiently heated and baked as baked in acasserole. As a cooking time varied with quantities of the exothermicmaterial 25 and a quantity of water is predetermined according to avariety and a quantity of dried noodles, after a predetermined time, forexample five minutes, passes, the generation of the vapor of hightemperature is stopped upon eating and the temperature drops to about100° C. with the completion of cooking. Therefore, the noodles arecooked in a state in which there is little water on the surfaces of thenoodles, resulting in a good taste which can not be obtained fromnoodles heated by hot water. Moreover as described above, quantities ofthe exothermic material (calcium oxide) 25 and water are properly set inadvance, the generation of the vapor of a high temperature completes ina short time of one minute or two, and thus prevention against anunusually high temperature is ensured. Further, even if some vaporleaks, through the aperture G1 and the small aperture G2, to the outsideof the body of the container, as the edge of the engagement part 23c ofthe container 3 is directed downward, the vapor would be dispersed, thusprevention against danger of a scald is ensured. Even if tho heatingcontainer 1 is discarded after the meal, due to the decrease in thetemperature of the container after the heating, a problem of a fire doesnot arise.

The heating device has an approximate square-shape suitable for cookingnoodles, however, according to a variety of food, it may be round orrectangular just like a lunch box. A variety of cooked food is notlimited to the dried noodles such as the "instant baked noodles", butbroadly general food may be cooked.

INDUSTRIAL UTILITY

As described above, according to the present invention, a heating devicewith use of heat of hydration reaction with an exothermic material andwater can add vapor of a high temperature generated by the heat to amaterial to be heated there below, in addition to conductive heattransferred through a wall of a container for the material to be heated,thus making it possible to effectively heat the material to be heated.

The heating device according to the present invention is, therefore,made simple but increases its uses compared to a conventional heatingdevice utilizing heat of hydration reaction with limited uses.

The invention being thus described, it will be obvious that the same maybe varied in many ways. Such variations are not regarded as a departurefrom the spirit and scope of the invention, and all such modificationsas would be obvious to one skilled in the art are intended to beincluded within the scope of the following claims.

What is claimed is:
 1. A steam direct heating device comprising:aheating container for generating a hot steam by an exothermic reactionsufficient to heat a cooked food and a food container housing the cookedfood to be heated, having apertures in a portion of a bottom wallthereof for passing the hot steam and being positioned over the heatingcontainer, wherein the heating container has an opening on an upper sidethereof; a first bag containing calcium oxide as exothermic materialsand a second bag containing water, the first and second bags beinglocated in the container and the first bag being positioned over thesecond bag; a sheet-type filter provided over the opening of thecontainer, the filter preventing exothermic materials from leaving thecontainer; and means for exposing the exothermic materials in the firstbag to water in the second bag to thereby start an exothermic reactionreleasing a high temperature steam, the steam passing through thesheet-type filter but the exothermic materials being prevented frompassing through the filter even when the exothermic materials areconveyed by water splashing in the exothermic reaction.
 2. The heatingdevice as recited in claim 1, wherein the means for exposing comprises atear element for tearing at least one of the first and second bags. 3.The heating device as recited in claim 2, wherein the tear element has atape-shape, the tear element is affixed to the second bag so thatpulling of the tear element opens the second bag, the tape-shape tearelement having a portion extending outside of the heating device.
 4. Theheating device as recited in claim 1, further comprising a removable lidpositionable on the heating device.
 5. The heating device as recited inclaim 4, wherein the lid has slits through which the vapor in thematerial container can be vented.
 6. The heating device as recited inclaim 5, wherein the material container is divided by a plurality ofpartitions into a plurality of material portions, the material portionsbeing generally separated from one another, the lid having ridgestherein for engaging the partitions and separating the materialportions.
 7. The heating device as recited in claim 6, wherein theridges have partition ribs defined therein, the ribs aiding inseparating the material portions, the ribs being engageable with thepartitions.
 8. The heating device as recited in claim 7, wherein atleast one of the partitions has a slit-shaped aperture defined therein,the at least one partition being hollow and extending above thecontainer with the first and second bag, vapor from the exothermicreaction travels through the at least one hollow partition and exitsthrough the slit-shaped aperture such that material in at least onematerial portion adjacent the at least one hollow partition is heated bythe vapor from above and from below.
 9. The heating device as recited inclaim 8, wherein the partition ribs on the lid engage the at least onehollow partition on one side of the slit-shaped aperture such that vaporcan escape to the one material portion on an aperture side of the atleast one hollow partition but vapor will fail to pass from theslit-shaped aperture to a second material portion on the other side ofthe at least one hollow partition.
 10. The heating device as recited inclaim 9, wherein the material container has a plurality of engagementribs around a periphery thereof, the engagement ribs being engageablewith the lid.
 11. The heating device as recited in claim 1, wherein thematerial container is divided by a plurality of partitions into aplurality of material portions, some of the material portions having theapertures in a bottom thereof such that material therein is heated bythe vapor and some of the material portions failing to have theapertures such that material therein fails to be heated by the vapor.12. The heating device as recited in claim 11, wherein the partitionsare generally hollow, at least one of the partitions being located abovethe container having the first and second bags while at least one secondpartition is spaced from the container having the bags, vapor from theexothermic reaction traveling through the at least one partition abovethe container having the bags while vapor fails to travel through the atleast one second partition.
 13. The heating device as recited in claim12, wherein the at least one second partition acts as an insulatorbetween a material portion with apertures on the bottom thereof and amaterial portion without apertures on the bottom thereof.
 14. Theheating device as recited in claim 1, wherein the material container isdivided into a plurality of material portions by at least one hollowpartition, at least one of the partitions being located above thecontainer having the first and second bags such that vapor from theexothermic reaction can travel therethrough, the at least one partitionhaving an aperture on an upper end thereof for escape of the vapor. 15.The heating device as recited in claim 1, wherein the bottom wall of thematerial container has a wavy shape.
 16. The heating device as recitedin claim 1, wherein the material container and the container having thefirst and second bags are readily detachable from the heating container.